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Biomedical subjects

A Peura

Publications and source records attributed to A Peura.

5 recordsLinked to original sources
PubMed1988

Ultrarapid freezing of early cleavage stage human embryos and eight-cell mouse embryos.

Early cleavage stage human embryos and 8-cell mouse embryos were snap-frozen after a brief exposure to high concentrations of dimethyl sulfoxide (DMSO; 2 or 3.5 M) and 0.25 M sucrose and thawed in a warm water bath. Eleven of 12 3- to 8-cell human embryos survived freezing and thawing with more than 50% of their original blastomeres intact. However, pregnancy was not initiated when the 11 embryos were transferred to six patients. It was shown that continuation of embryonic development in vitro and in vivo was significantly better when 8-cell mouse embryos were snap-frozen in 3.5 M DMSO than in 2 M DMSO. When frozen in 3.5 M DMSO, 78% of 8-cell embryos survived on thawing, 84% developed to blastocysts in vitro, 63% implanted, and 42% developed to fetuses. Ultrarapid freezing is a quick and inexpensive method for mouse embryo cryobanking, but further studies are required to confirm the viability of frozen human embryos.

Animals↗
PubMed1987

Ultrarapid freezing: a new low-cost and effective method of embryo cryopreservation.

The authors describe a rapid freezing method (ultrarapid freezing) that has been developed for cryopreservation of early cleavage stage embryos. In the present experiments, 2-cell mouse embryos were frozen under a wide range of conditions in an attempt to optimize their survival and viability in vitro and in vivo. The experiments show that embryos exposed briefly (2 to 2.5 minutes) to relatively high concentrations of dimethyl sulfoxide (3 to 4 M) and 0.25 M sucrose survive and develop when plunged directly into liquid nitrogen and thawed in a 37 degrees C waterbath when sealed in 0.25-ml plastic pailettes. Survival and viability rates of ultrarapidly frozen embryos after thawing were comparable to those obtained with conventional slow-freezing techniques. The authors believe that this freezing technique can be further improved and that the speed, ease, and low cost of the method make it a very attractive alternative to more conventional methods for freezing early cleavage stage embryos.

Animals↗
PubMed1985

T-antigen expression by peanut agglutinin staining relates to mucosal dysplasia in ulcerative colitis.

Staining of 326 rectal mucosal biopsies from ulcerative colitis patients with peanut agglutinin (PNA), which binds to the T-blood group antigen and has been claimed to reflect a cancer-associated mucin alteration, showed highly significant direct associations with mucosal dysplasia (P less than 0.001), disease activity (P less than 0.001), and subsequent development of rectal cancer in a smaller series of patients (P = 0.005). Staining for normal colonic mucin by the Dolichos biflorus (DBA) lectin related significantly and inversely to dysplasia. Intense normal colon mucin staining by DBA related significantly (P less than 0.025) to long disease duration and to subsequent development of cancer (P = 0.02). The latter association is based on a small number of patients only and is not considered conclusive evidence, but may provide a link with goblet-cell hyperplasia. The authors conclude that although T-antigen expression relates to dysplasia, the findings of "false" positive and negative rates of 22 and 33 percent respectively, make it unlikely that staining of biopsy sections for the T-antigen by peanut agglutinin will contribute materially to routine assessment for dysplasia and cancer risk prediction in patients with ulcerative colitis.

Adult↗